Safety ignition device for gas



March 14, 1944. HEGWE 2,343,904

SAFETY' IGNITION DEVICE FOR (ms BURNERS v Filed Feb.' 27, 1939 5Sheets-Sheet 1 Jaye/2MP:

March 14, 1944. HEGWElN 2,343,904

SAFETY IGNiTION DEVICE FOR GAS BURNERS Filed Feb. 27. 1959 5Sheets-Sheet 2 u: 23 f; 25 I Jarenfar:

Filed-Feb. 27; 1939 5 Sheets-Sheet 3 March 14, 1944. HEGwEm 2,343,904

SAFETY IGNITION DEVICE FOR GAS BURNERS Filed Feb. 27, 1939 5Sheets-Sheet 4 I 23 v V 40 March 14, 1944. HEGwEjN 2,343,904

SAFETY IGNITION DEVICE FOR GAS BURNERS Filed Feb. 27, 1939 5Sheets-Sheet 5 Patented Mar-.14, 1944 UNITED STATES PATENT oFFu:

SAFETY IGNITION DEVICE FOR GAS BURNERS Georg Hegwein, Dessau, Germany;vested in the Alien Property Custodian Application February 27, 1939,Serial No. 258,83 In Germany March 8, 1938 17 Claims.

The invention relates to a safety ignition device for gas burners inwhich the supply of gas to the pilot flame and main burners iscontrolled by a thermostat heated by the pilot flame.

In previously proposed arrangements of this kind the main gas valve andpilot flame valve have been connected with a control rod actuated by thethermostat in such a manner that on the thermostat becoming heated themain gas valve is opened and the supply of gas to the pilot flame isthrottled whilst on-the-othenhand when the thermostat cools down themain gas valve is closed and the pilot flame valve opened. In

. such case, although the supply of gas to the It is an object of theinvention to provide a thermostatically controlled safety ignitiondevice for gas burners having means for controlling the supply of gas tothe pilot flame and main burner.

Another object of the invention is to provide a safety ignition devicewherein the pilot flame valve and the main gas valve are opened insuccession after a predetermined interval.

A further object of the invention is to provide an arrangement whereinin the event of the extinction of the pilot flame the gas supply to themain burner and to the pilot flame are cut off.

It is a still further object of the inventionto provide an ignitiondevice for a gas burner wherein a single thermally responsive device isadapted to actuate both the pilot flame valve and the main gas valve.

It is a still further object to provide a gas burner ignition devicewhich is adapted to be set in operation by a manually operated pressknob and having means whereby the gas supply to the main burner andpilot burner are thereafter automatically regulated;

Other objects of the invention willappear from the following descriptionand appended claims when considered in connection with the accompanyingdrawings forming part of this specification.

According to the present inventionthe valves for supplying gas to thepilot flame and main burner are so arranged and combined with thecontrol device actuated by the thermostat that when the thermostat isheated the valve for the' pilot flame gas and that for the main supplyopen in succession after a predetermined lapse of time and are closed inreverse order when the thermostat cools down.

' The result of this arrangement is that after the extinction of thepilot flame the supply of gas both to the main burner and the pilotflame is cut off. In this case the pilot flame nozzle may haveacomparatively wide bore so that the troublesome choking due to gum isobviated and a rapid uninterrupted flow of gas through the pilot flamepipe accompanied by accelerated opening and thereforerapid controlaction of thedevice is obtained.

To enable the invention to be fully understood it will now be describedwith reference to the accompanying drawings in which five typicalembodiments of the invention are illustrated in Figs. 1-5, which arelongitudinal sectional views. in all these embodiments substantiallycorresponding parts are indicated by the same reference numerals.

-The safety ignition device according to Fig. 1 comprises a casing I,with .a branch 2 for connection with a gas-supply pipe and a branch 3'ror connection with the main burner. Arranged on the casing I is athermostat 4 composed of a bimetallic strip, the free end of which isconnected with a control rod 5 axially displaceable I in the casing I.Said rod 5 rests on the head 6 or a coaxially arranged thrust rod 1adapted to slide in a valveplate 8. The plate 8 is held in the closedposition by a spring 9 and is provided on its lower end with a tubularextension H provided with transverse bores l0 and is slidably guided ona tube I2 adapted to be axially displaced by means of a push knob l3(against the action of a spring M) in a guide member l5 which is screwedinto the casing I. At the same I time the stroke of the tube I2 ispreferably restricted by suitable means. At the end facing the knob l3the tube I2 'is fitted with a gastight packing and is provided at itsupper end with an opening l6 below which is located inside the tube aball valve I! held in the closing position by a spring l8. The ballvalve ll faces the lower end of the thrust rod I through the opening ISwith or without a predetermined amount of lost motion. Below the tubularextension ll of the valve plate 8 the guide member I is provided with avalve'seating IQ for the tube I2. The guide member I5 is provided with ahorizontal bore 20 extending right through and communicating with thevalve seating 19 through a widened bore 2| and with the interior of thetube I2 through bores 22. A tube 23 leading to the pilot flame nozzle 24also communicates with the bore 20.

The arrangement according to Fig. 1 functions in the following manner:When the various parts are set in the positions shewn in Fig. 1 thearrangement is in the inoperative position. To set it in operation anupward pressure is applied to the knob l3. By this means the tube [2 iscorrespondingly raised from the valve seating I9 so that the gasentering through the branch 2 can flow past the valve seating I9, bores2| and 20 and the tube 23 of the pilot flame nozzle 24. Raising the tubel2 by means of the knob l3 also causes the ball valve I! to be openedbut ince the tub 12 also closes the bores H) the opening of the valve I1is inoperative for admitting the gas to the pilot flame nozzle.Consequently the supply of gas to the pilot flame burner 24 takes placeat first only by way of the valve seating 19 in the manner alreadydescribed.

If the gas issuing from the nozzle 24 be now ignited the pilot flameheats the bimetallic strip 4, the free end of which then depresses thecon trol rod 5 and therewith the thrust rod 1 which opens the ball valvell more fully against the action of the spring l8. After a shortinterval the knob l3 may be released whereupon it is returned to itsoriginal position by the spring l4. At the same time the tube I2 also isreturned into its original position to seat on the valve seating 19.However, since the tub l2 has again uncovered the transverse bores I0 inthe tubular extension ll of the valve plate 8 and the thrust rod 1,correspondingly depressed by the thermostat 4 keeps the ball valve I!open, gas is now supplied to the pilot burner nozzle 24 through thebores ID, the ball valve l1 and the bores 22 of the tube l2 and the bore20 communicating with the tube 23 so that the pilot flameis notinterrupted.

The continued heating of the thermostat 4 by the pilot flame depressesthe control rod 5 still further so that the head 8 of the thrust rod 1bears against the valve plate 8 and moves it from; its seating againstthe action of the spring 9. In this'way gas is also admitted to the mainburner connected with the branch 3 and this gas is then ignited by thepilot flame in known manner.

when the valve plate 8 is depressed by the head 6 the'bores I0 providedin the tubular extension l I of the valve plate also occupy acorrespondin ly lower level and thus become more or less covered by theupper end of the tube 12.,

The supply of gas to the pilot flame nozzle 24 is thus throttled in sucha manner that the pilot flame continues to burn with only justsuflicient power to keep the valve plate I in the openposition. It thegas supply to the nozzle 24 be insufllcient to enable this condition tobe maintained the valve opening action of the thermostat 4 will diminishand the valveplate 8 will be lifted by the spring 8. Thefree apertureotthe bores ll will thus increase accordingly so that the supply ofcaste the pilot flame male 24 is increased and the more highly heatedthermostat will depress the valve plate 8 accordingly against the actionof the spring 9. Consequently the supply of gas to the nozzle 24 and themain burner is regulated automatically.

If the knob l3 be held too long in the upward position the pilot flameburner 24 will receive an undiminished supply of gas owing to the tubei2 being maintained above the valve seating IS. The thermostat 4 willtherefore be intensely heated and thus exert a powerful downwardpressure on the valve plate 8. The opening stroke of the plate 8,however, is limited by the tubular attachment H, the lower end of whichseats itself on a corresponding flat surface of the guide member I5 andthus interrupts the supply of gas past the valve seating l9 so that thepilot flame goes out. This arrangement prevents, therefore, thethermostat 4 from becoming damaged.

If the pilot flame be extinguished and the heating of the thermostatthus ceases the free arm of the thermostat 4 returns to its originalposition, the valve plate 8 being returned to its original closingposition by the spring 9 and the ball valve I'I similarly closed by thespring I8 so that the supply of gas is shut' off from the main burnerand also the pilot burner nozzle 24.

The arrangement of the transverse bores I0 for supplying gas to thepilot burner nozzle is noteworthy. These bores are comparatively wideand are arranged in such a manner as to be partially covered by theupper part of the'tube l2 even when in the inoperative position. Theresult of this arrangement is that a sufilcient aperture for the supplyof gas is normally available whilst even a comparatively slight loweringof the valve plate 8 from its seat is enough to throttle the supply ofgas to the nozzle 24 considerably. The possibility is also afforded ofproviding the pilot burner nozzle with a comparatively wide aperturewhich as already mentioned is of advantage in many respects.

Owing to the relatively slidable telescopic tubular members i l and i2for controlling the sup- .ply of gas the structural height of the entirearrangement can be kept low and the design as a whole made comparativelysimple.

The arrangement according to Fig. 2 differs from that described withreference to Fig. 1 flrstly in that the ball valve l7 and its closingpring iii are located in a fixed (and not slidable) tube 25 which forexample is integral with a closure member 25 adapted to be screwed intothe casing I. The free space in which the spring I8 is situatedcommunicates with the tube 23 supplying gas to the pilotburner nozzle 24by way of a bore 21 in the member 26 and a passage 28 in the casing i.In this case the gas is supplied to the main burner by a branch 3attached to the space above the valve plate 8." To make the arrangementready for lighting up, the casing I is provided with a press knob 29adapted to be depressed against the action of an inte riorly housedspring (not shown). Said knob has a widened rim 30 which when the knobis depressed depresses the control rod 5 and therefore the thrust rod 1accordingly. In this'way the ball valve I1 is opened so that in contrastprolonged actuation of the knob will not affect the functioning of thearrangement.

When made ready for lighting. up, the arrangement according to Fig. 2functions in precisely the same manner as that according to Fig.1.

The arrangement according to Fig. 3 corresponds with that according toFig. 2 in so far that in this case also a press knob 29 is provided onthe casing for preparing the conditionsfor lighting up.

According to Fig. 3 the gas is supplied through a branch 2 arranged onthe rear side of the example shewn. The main'burner is connected withthe branch 3. The ball valve l1 and its closing spring I8 are housed ina fixed tube 3| which is integral with a diaphragm housing 32 screwedinto the lower end of the casing cated in the lower end of the tube 3|is a second ball valve 33 whilst similarly to the case of Fig. 2 theinterior space of the tube 3| communicates with the tube 23 supplyinggas to the pilot burner 11 zzle 24 through bores 34 in the diaphragmhens and a passage 35 in the casing i. The housing 32 is provided with adiaphragm 36 which when in the inoperative position is pressed upwardsby a spring 31 and thus keeps 4| and thus controls the supply of gaspassing in the first place through the passages 44, 45, 46 and tube 23to the pilot-bumer nozzle 24. Also branching from the tube 4| is apassage 41 to which is attached a tube 48 the other end of whichcommunicates with the passage 45. A known instrument 49 forautomatically controlling the supply of gas through the tube 48 inaccordance with the room temperature is located at a suitable point insaid tube 48.

The arrangement according to Fig. 4 functions 1 in the following manner.After making ready for lighting up by depressing the knob 29 the gassupply to the pilot burner nozzle 24v proceeds by way of the bores |0,the opened ball valve H, the tube 4| and the passages 43, 44, 45 and 43.After the thermostat 4 has become hot enough to cause the head 6 of thethrust rod 1 to move the valve plate 8 from its seating, the volumecontrol pin is also depressed sufllciently to close the bore 43. Thesupply of gas to the pilot burner nozzle 24 now takes place by way ofthe passage 41, tube 48 and passages 45, 45 The control instrument 49which is set to act at a predetermined temperature now controls thesupply of gas to the pilot burner nozzle in known manner, the supply theball valve 33 open by means of a pin 38 adapted to slide axially in thediaphragmhousing.

Beyond the main valve plate 8 the conduit sup-' plying gas to the mainburner is placed in communication with the space above the diaphragm 36through a passage 39.

The arrangement according to Fig. 3 functions in the following manner:Making ready for,

38 shares the movement of the diaphragm thus more or less lowering theball valve 33 so that under the action of the spring |8 the supply ofgas to the pilot burner is correspondingly throttled by the valve 33.The resulting lowering of the pilot flame and the consequentlydiminished heating of the thermostat 4 adjusts the valve plate 3 in sucha manner that the gas pressure in the supply pipe for the main burner ismain-.

tained at a predetermined constant level that v is to say the supply ofgas to the main burner is automatically controlled in accordance withthe 888 DI'GSSIIIB.

Fig. 4 represents an arrangementin which the gas supply is controlled inaccordance with a predetermined temperature such as room temof gas tothe main burner being thus controlled by the corresponding adjustment,already described with reference to Fig. 2, of the valve plate 8 by thethermostat 4'. I I

The arrangement according to Fig. 5 differs in the first place from thataccording to Fig. 2 in I that the tubular extension of the valve plate 3is perature. By comparison with the arrangement according to Fig. 2 thatshewn in- Fig. 4 differs in respect of the design of the lower portion-In the case of Fig. 4 this portion comprises an attachment 40 which isscrewed into the casing and is integral with a tube 4| housing the ballvalve II. In this case the ball valve-l1 rests on a volume control pin'42 which, when the arrange-.

ment is out of. action. is lifted bythe spring IS in such amanner as tohold the ball valve I! in the closed position. The lower end of the pin42 of the tube 50 communicates with the nozzle 24 in a similar way tothe arrangement according to Fig. 2.

The arrangement according to Fig. 5 functions in the following manner. aThe arrangement is made ready as in the case of Fig. 2. If now, as

theresult of the thermostat becoming too inbe automatically controlledin a manner otherwise corresponding with Fig. 2.

I In its manner of operating, the device for controlling the supply ofgas to the pilot burner in the arrangement according to Fig. '5,corresponds with the volume'control pin 42 actuated by the pilot flamevalve l1 and coacting with a bore 43, according to Fig. 4. Consequentlyin the "case also of the arrangement according to Fig. ,4,

the tubular extension l| employed in connection with the main gas 'valve8 for controlling the gas supply to the pilot flame could be, omitted Iclaim: g 1. A safety ignition device .for gas burners comprising apilot-flame valve, a main gas valve,'a thermostat adapted to be heatedby the pilot flame, a control device actuated by said thermostat, saidcontrol device directly engaging and operating said valves so that, whenthe thermowith means for progressively throttling of the pilot gas whenthe main gas valve is moved by the thermostat beyond its completely openposition.

2.-A device according to claim 1 wherein the main gas valve comprises avalve plate which is retained in the closed position by a spring whilstthe pilot-flame gas valve consists of a ball valve which is retained inthe closing position by a spring, the two valves being independentlyslidable in the same axial direction and opened or closed by movement inthe same direction.

3. A device according to claim 1 wherein a control rod actuated by thethermostat acts on a thrust rod, one end of which passes through themain gas valve and actuates the pilot-flame valve, whilst its other endis provided with means adapted to actuate the main gas valve.

4.-A device according to claim 1 whereinthe pilot-flame valve is housedin a tube and the tubular means is slidably mounted by said tube.

5. A device according to claim 1 wherein the pilot-flame valve is housedin a tube and said tubula means is slidably mounted by said tube, saidopenings being arranged so as to be correspondingly more or less coveredby the tube as themain gas valve is opened.

6. A device according to claim 1 wherein the pilot-flame valve is housedin a tube and said tubular means is slidably mounted on said tube, saidopenings being of comparatively large cross section and being arrangedin such a manner as to be partially covered by the tube even when thedevice is in the inoperative position.

7. A device according to claim 1 wherein a press knob device is providedwhich is operated to open a supplemental supply of gas' to the pilotflame in order to set the device in operation.

8. A device according to claim 1 wherein the pilot-flame valve is housedin a tube and said tubular means is slidably mounted on said tube, thetube housing the pilot flame valve being mounted so as to be axiallydisplaceable by means of a press knob against the action of a spring, anauxiliary valve being provided for a supplemental supply of gas to thepilot flame, this latter valve being against the control device actuatedby the thermostat in such a manner as to open the pilotflame valve. 1

10. A device according to claim 1 wherein the pilot-flame valve ishoused .in-a tube and said tubular means is slidably mounted on saidtube, a second valve being located in the tube housing the pilot-flamevalve and by means of 2. diaphragm pressure regulator attached to thecasin controls the supply of gas to the pilot-flame burner in accordancewith the gas pressure prevailing in'the'gas supply pipe to the mainburner.

valve in the tube housing the latter by means of which the pilot-flamevalve is adapted to throttle the supply of gas to the pilot flame whenin the fully open position.

12. A device as set out in claim 1 including an auxiliary valvecontrolling a supplemental supply of gas to the pilot flame, and amanually operated device for actuating said auxiliary valve.

13. A safety ignition device for gas burners having a pilot flame valve,a main gas valve, a thermostat adapted to be heated by said pilot flame,both valves being operable by said thermostat, a rod connected to saidthermostat for actuating said valves, said rod being in constantpositive connection with said pilot flame valve and having means whichare brought in positive connection with said main gas valve to actuateit after the rod has opened the pilot flame valve and a tubular meansconnected with said main gas valve and operable thereby, said tubularmeans surrounding the pilot valve and being provided with openings forthe passage of the pilot gas and being further provided with means forprogressively throttling the passage of the pilot gas when the main gasvalve is moved by the thermostat beyond its completely open position.

14. A device according to claim'13 wherein the rod actuated by thethermostat comprises a thrust rod, one end of which passes through themain gas valve and actuates the pilot-flame valve, while its other endis provided with a head adapted to actuate the main gas valve.

15. A safety ignition device for gas burners comprising a thermostatheated by a pilot flame, a pilot-flame valve and a main gas valve whichare opened and closed in succession by said thermostat, and additionalvalve means arranged c0- axially of and operatively connected to saidmain valve and controlling the supply of gas to the pilot flame wherebythe supply of gas to the pilot flame is progressively throttled by saidvalve means when said main gas valve is moved beyond its completely openposition.

17. A safety ignition device for gas burners comprising a thermostatheated by a pilot flame, a pilot-flame valve, a main gas valve, acontrol device actuated by said thermostat, said control device directlyengaging and operating said valves so that, when the thermostat isheated, first the pilot flame valve and then after a predetermined lapseof time the main gas valve are opened in succession by saidthermostatically actuated contrbl device, said valves being closed inreverse order when the thermostat cools down, and valve means arrangedcoaxially of and operatively associated with said main gas valve, saidcontrol device operat ng said valve means to control the supply of gasto the pilot flame whereby, the supply of gas to the pilot flame isprogressively throttled by said valve means when said main gas valve ismoved beyond its completely open position.

GEORG HEGWEIN.

